• Parasites, Hosts and Diseases
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• v.43 no.4 s.136
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• pp.161-164
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• 2005

A survey was performed in order to determine the infection status of the metacercariae of heterophyid fluke in two goby species, Boleophthalmus pectinirostris and Scartelaos sp., collected from Gangjin-gun, and Shinan­gun, Sooncheon-shi, Jeollanam-do, Republic of Korea. A total of three metacercariae of Heterophyopsis continua was found in only one B. pectinirostris $(10.0\%)$ from Gangjin-gun. Heterophyes nocens metacercariae were detected in 24 B. pectinirostris $(96.0\%)$ and 14 Scartelaos sp. $(63.6\%)$ from Shinan-gun. Heterophyopsis continua metacercariae were found in 11 B. pectinirostris $(44.0\%)$ and 21 Scartelaos sp. $(95.5\%)$ from Shinan-gun. Stictodora fuscata metacercariae were detected in 18 B. pectinirostris $(72.0\%)$ from Shinan-gun. No metacercariae were detected in 20 B. pectinirostris from Sooncheon-shi. From the above results, this study is the first to prove that B. pectinirostris and Scartelaos sp. serve as the second intermediate hosts of some heterophyid flukes in Korea.

• Parasites, Hosts and Diseases
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• v.58 no.4
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• pp.373-386
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• 2020

Fish-borne heterophyid trematodes are known to have a zoonotic potential, since at least 30 species are able to infect humans worldwide, with a global infection of around 7 million people. In this paper, a 'state-of-the-art' review of the South American heterophyid species is provided, including classical and molecular taxonomy, parasite ecology, host-parasite interaction studies and a list of species and their hosts. There is still a lack of information on human infections in South America with undetected or unreported infections probably due to the information shortage and little attention by physicians to these small intestinal flukes. Molecular tools for specific diagnoses of South American heterophyid species are still to be defined. Additional new sequences of Pygidiopsis macrostomum, Ascocotyle pindoramensis and Ascocotyle longa from Brazil are also provided.

• Parasites, Hosts and Diseases
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• v.45 no.1 s.141
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• pp.33-38
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• 2007

To know the prevalence of heterophyid trematodes among inhabitants of a southern coastal village, i.e., Sacho-ri, Gangjin-gun, Jeollanam-do(Province), 82 stool samples were examined on helminth eggs and protozoan cysts using Kato-Katz and formalin-ether sedimentation techniques. Total 33 people(40.2%) were positive for trematodes(Heterophyes nocens; 15 people, Pygidiopsis summa; 3, Metagonimus sp.; 4, Clonorchis sinensis; 7, Gymnophalloides seoi; 6) and/or protozoa(Entamoeba coli; 3). Among intestinal trematode egg positive cases, 17 were treated with praziquantel and their whole diarrheic stools were collected after purgation. Adult flukes of H. nocens(number of specimens=1,294), P. summa(386), Stellantchasmus falcatus(5), Stictodora lari(4), and Heterophyopsis continua(1) were collected using a stereomicroscope. To know the source of human H. nocens infections in this village, metacercarial infections in mullets(10) were examined and most H. nocens metacercariae(101/105, 96.2%) were found in the trunk portion. From above results, the surveyed coastal village has been newly known as an endemic focus of human H. nocens infection and consuming raw mullets was the presumable source of human heterophyid infections.

• Parasites, Hosts and Diseases
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• v.44 no.1 s.137
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• pp.7-13
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• 2006

Heterophyid metacercarial infections in brackish water fishes, i.e., perch, shad, mullet, redlip mullet, and goby, of Jinju-man (Bay), Kyongsangnam-do, Korea, were investigated using a digestion technique. Among 45 perch (Lateolabrax japonicus), the metacercariae of Heterophyopsis continua were found in $55.6\%$ (18.5 metacercariae per fish), Stictodora spp. in $28.9\%$ (3.6), and Metagonimus takahashii in $6.7\%$ (17.0). The metacercariae of H. continua were detected in 23 $(65.7\%)$ of 35 shad (Konosirus punctatus). Among 15 mullet (Mugil cephalus), the metacercariae of Pygidiopsis summa were found in $100\%$ (105.9 metacercariae per fish), Heterophyes nocens in $40.0\%$ (8.5), H. continua in $13.3\%$, and Stictodora spp. in $6.7\%$. Among 12 redlip mullet (Chelon haematocheilus), the metacercariae of P. summa were detected in $91.7\%$ (1,299 metacercariae per fish), H. nocens in $16.7\%$, and Stictodora spp. in $16.7\%$. Among 35 gobies (Acanthogobius flavimanus), the metacercariae of Stictodora spp. were found in $82.9\%$ (44.5 metacercariae per fish), and H. continua in $25.7\%$ (2.8). The adult flukes recovered from a cat experimentally infected with metacercariae from perches were compatible with M. takarashii. The results confirm that the estuarine fish in Jinju-man (Bay) are heavily infected with heterophyid metacercariae. Furthermore, it was found for the first time that the perch acts as a second intermediate host for M. takahashii.

• Parasites, Hosts and Diseases
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• v.59 no.3
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• pp.303-309
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• 2021

In this study, we intended to describe an unrecorded species of heterophyid trematode recovered from the small intestine of a Korean raccoon dog, Nyctereutes procyonoides koreensis, in Korea. A total of 13 small flukes were collected from a deceased Korean raccoon dog which was found in Chuncheon-si, Gangwon-do, Korea in May 2017. The trematode body were covered with many small spines, rectangular, broader than long, 807-1,103 ㎛ long and 1,270-1,550 ㎛ wide. Oral sucker in the anterior end slightly smaller than acetabulum. Pharynx muscular and well developed. Esophagus relatively long and sigmoid. Acetabulum small and located at median in anterior 2/5 portion. Ceca bifurcated at the anterior of genital pore and acetabulum and terminated at testis level. Testes larger, deeply lobed and located at the near of posterior end of body. Ovary small, triangular and located at the slight left of median and the anterior of left testis. Vitelline follicles dendritic and extend from the middle level of esophagus to the posterior portion of body. Eggs embryonated, operculated, small and 33-35×15-16 ㎛ in size. Based on the morphological characteristics, the small heterophyid flukes recovered from the small intestines of Korean raccoon dog, N. procyonoides koreensis, were identified as Euryhelmis squamula (Digenea: Heterophyidae). Accordingly, this species of heterophyid flukes is to be a new trematode fauna in Korea by this study.

• Parasites, Hosts and Diseases
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• v.48 no.2
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• pp.133-138
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• 2010

Infection status of intestinal flukes was investigated in residents of Muan-gun, Jeollanam-do, the Republic of Korea. Total 1,257 fecal samples of residents were examined by formalin-ether sedimentation technique and Kato-Katz thick smear method. Helminth eggs were detected from 95 (7.6%) residents, and eggs of heterophyid flukes and Clonorchis sinensis were found from 62 (4.9%) and 40 (3.2%) cases, respectively. The larger heterophyid eggs, somewhat darkbrown in color and $37.7{\times}21.5{\mu}m$ in average size, and found in 32 (2.6%) out of 62 egg positive cases of heterophyid flukes. To confirm the adult flukes, we performed worm recovery from 12 cases after praziquantel treatment and purgation with $MgSO_4$. A total of 1,281 adult flukes, assigned to 7 species, were recovered from 9 cooperative cases. Heterophyes nocens (total 981 specimens) was collected from 9 cases, Stictodora fuscata (80) from 7, Gymnophalloides seoi (75) from 5, Pygidiopsis summa (140) from 3, Stellantchasmus falcatus (3) from 2, and Stictodora lari and Acanthotrema felis (each 1 worm) from 1 case each. The intrauterine eggs of S. fuscata collected from the recovered worm were identical with the larger heterophyid eggs detected in the stool examination. By the present study, it was confirmed that A. felis is a new intestinal fluke infecting humans, and residents in Muan-gun, Jeollanam-do are infected with variable species of intestinal trematodes.

• Biomedical Science Letters
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• v.7 no.1
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• pp.31-37
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• 2001

The present study was performed to investigate the infection status of heterophyid fluke metacercariae in mullets and gobies collected from some coastal areas of cholla-do. The collected fishes were transferred to the laboratory, artificially digested with pepsin-HCI solution and examined under a stereomicroscope. In 70 mullets examined, the metacercariae of Heterophyes nocens (in 28.6% of fish), Heterophyopsis continua (in 2.9%), Pygidiopsis summa (in 32.9%) and Stictodora spp. (in 14.3%) were detected. The metacercariae of H nocens were detected in mullets from Shinan-gun (in 60.0% of fish), Muan-gun (in 54.4%), Hampyong-gun (in 25.0%) and Yonggwang-gun (in 16.7%). The average metacercarial density per infected fish were 7.6,34, 10 and 5 in each areas. A total of 7 metacercariae of H. continua was detected in only 2 mullets from Hampyong-gun. The metacercariae of p. summa were detected in mullets from Haenam-gun (in 80.0% offish), Muan-gun (in 27.3%), Hampyong-gun (in 16.7%) and Puan-gun (in 100%). The average metacercarial density per infected fish were 350, 14, 5 and 97 in each areas. The metacercariae of Stictodora spp. were detected in mullets from Shinan-gun (in 26.7% offish), Hampyong-gun (in 33.3%) and Puan-gun (in 20.0%). The average metacercarial density per infected fish were 2.8, 18.8 and 2.5 in each areas. In 70 gobies examined, the Metacercariae of H nocens (in 15.7% of fish), H continua (in 47.1%) and Stictodora spp. (in 48.6%) were detected. The metacercariae of H. nocens were detected in gobies from Shinan-gun (in 50.0% of fish) and Yonggwang-gun (in 10.0%). The average metacercarial density per infected fish were 71 and 2 in each areas. The metacercariae of H. continua were detected in gobies from Shinan-gun (in 65.0% of fish), Hampyong-gun (in 70.0%) and Yonggwang-gun (in 60.0%). The average metacercarial density per infected fish were 5.7,6.6 and 3.2 in each areas. The metacercariae of Stictodora spp. were detected in gobies from Shinan-gun (in 80.0% offish), Hampyong-gun (in 70.0%) and Puan-gun (in 40.0%). The average metacercarial density per infected fish were 149,203 and 5.5 in each areas. From the above results, it was confirmed that the mullet and goby from some coastal areas of cholla-do are infected with numerous metacercariae of heterophyid trematodes.

• Parasites, Hosts and Diseases
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• v.46 no.2
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• pp.109-112
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• 2008

A parasitological investigation on trematode metacercariae was made on 62 freshwater fishes of 13 species in northern Thailand; Cyclocheilichthys apogon, Puntioplites proctozysron, Labiobarbus siamensis, Barbodes gonionotus, Barbodes altus, Henicorhynchus siamensis, Osteochilus hasselti, Notopterus notopterus, Mystacoleucus marginatus, Anabas testudineus, Systomus orphoides, Morulius chrysophykadian, and Hampala macrolepidota. The fish were caught over the summer period (February-May 2007) from 2 Chiang Mai water reservoirs, i.e., the Mae Ngad (UTM 47Q E 503200, 47Q N 2119300) and the Mae Kuang Udomtara (UTM 47Q E 513000, 47Q N 2092600) Reservoirs in Chiang Mai province, Thailand. The prevalence of heterophyid (Haplorchis taichui and Haplorchoides sp.) metacercariae in these fish was 83.9% and 74.2% in the Mae Ngad and Mae Kuang Udomtara Reservoirs, respectively. The highest intensity of heterophyid metacercariae in H. siamensis in the Mae Ngad was 120.4 and that in P. proctozysron in the Mae Kuang Udomtara was 180.0. The fish, A. testudineus, C. apogon, and M. chrysophykadian, were not found to be infected with H. taichui metacercariae. The results show that the freshwater fish in Chiang Mai water reservoirs are heavily infected with H. taichui and Haplorchoides sp. metacercariae.

• Parasites, Hosts and Diseases
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• v.37 no.3
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• pp.189-194
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• 1999

A case of human infection with Heterophyes nocens (Heterophyidae) was incidentally found in a biopsy specimen of the Meckel's diverticulum at the upper part of the small intestine. The patient was a 58-year-old man living in a rural area of Talsong-gun, Kyongsangbuk-do.He had gastrointestinal symptoms such as epigastric pain, indigestion, and abdominal discomfort for 3 months, and severe diarrhea, abdominal pain, and vomiting for about 1 month before hospitalization. Endoscopy of the upper part of the small intestine revealed a Meckel's diverticulum, and it was excised and histo-pathologically examined. Three adult flukes were incidentally found sectioned in the mucosa, and they were identified as H.nocens. The patient had a history of eating raw mullets at a fish market in Pusan 6 months ago, and the mullets were presumed to be the source of infection. This case brings a considerable interest in that specific diagnosis of heterophyid infections could be done by sectional morphology of the worms.

• Parasites, Hosts and Diseases
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• v.41 no.2
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• pp.107-111
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• 2003

The surface ultrastructure of Acanthotrema felis (Trematoda: Heterophyidae) adults, recovered from a kitten experimentally infected with the metacercariae, was observed using a scanning electron microscope. The worm was leaf-like, ventrally concave and covered with scale-like multi-pointed tegumental spines. The spines on the anterior surface were short but broad, and had 10-12 pointed tips. The cytoplasmic processes protruded around the spines, like pockets for the spines. The ventrogenital opening was crescent, or kidney-shaped, and had protuberances with minute spines on its surrounding tegument. The spines on the posterior surface were long, but narrow, with 6-8 pointed tips. The cytoplasmic processes on this tegument were ridge-like, and elevated along the row of the spines. The surface ultrastructure of A. felis is generally similar to that of other heterophyid flukes, but some features are characteristic, and may be of taxonomic and bio-ecological significance.